The Truth About Hillary
The "high crimes" in the Constitution's impeachment clause refers not to the nature of the crime, but to the high status of the offending officeholder. An offense need not be an actual part of the criminal code to warrant impeachment and removal from office. In other words, just being really awful at your job could get you removed from it. That's a powerful check on the executive and judicial branches -- if the political will exists in Congress to use it.
That's a mighty big "if."
The next two words are "and misdemeanors," indicating that the Founders thought that mere misdemeanors by officeholders could be grounds for removal from office. That's supposed to keep our officeholders on a tight leash, but in practice it hasn't always worked that way.
In office, Clinton's use of an unsecured private email server ought to have been an impeachable offense for the "high crime" of being too inept at her job to keep it. Clintonemail.com was the high-tech equivalent of sending old-fashioned radio communications unencrypted over public airwaves all across the globe. In the old days, a King would have summarily executed his foreign minister for such treachery. These days, the King gives her his tacit blessing to become his successor.
On Friday there was a minor brouhaha because "the White House is reportedly seeking to keep some emails between President Obama and former Secretary of State Hillary Clinton from being released anytime soon," but that's of not much concern. If a president and his secretary of State can't maintain private correspondence, then effective foreign policy is impossible -- the White House should be allowed broad latitude to keep private communications private. But the impeachable point of the matter is that the president and his secretary of State weren't maintaining private correspondence -- clintonemail.com makes it a near certainty that their communications were being read, perhaps in near-realtime, by the Russians, Chinese, and maybe even the Iranians.
What was that about the need for private correspondence being a necessity to an effective foreign policy? Look at the shambles of Obama's foreign policy if you harbor any doubts about Clinton's impeachably criminal negligence as SecState.
Of course, the existence of clintonemail.com didn't come to light until after Clinton had left office, rendering her immune from impeachment. It does however raise the question of why no one at State or in the White House questioned her reliance on a private email server, or why nobody seems to have given even a cursory look into its security.
More broadly, this incident raises the question of what to do with someone who committed impeachable offenses, but didn't get caught until after leaving office.